Heat exchanger



E. PRAT. HEAT- EXCHANGER, APELICATION FILED OCT, 29. 1920.

Patented Mar. 21, 1922.

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I HEAT EXCHANGER.

APPLlCATlON FILED OCT. 29.1920.

1,409,967., Patented marfzl, 1922.

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E. PRAT.

HEAT EXCHANGER.

APPLICATION HLED OCT. 29,1920.

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Patented Mar. 21, 922.

EMILE 1 mm, or rams. FRANCE iina'r EXCHANGER.

To all whom it may concern:

Be it known that I, Emu: Paar, citizen of the Republic of France. residingat Paris. France, 64 Rue de Miromesnil. have invented certain new and useful Improvements in Heat Exchangers of which the following is a specification.

My invention relates toa heat-exchanger of the plate type. Exchangers of this type as generally used are composed of lamellar members usually made Oi; ectan ular semi-circular sheets" of'metal',"'sepa1-ated either by a beading round their edges, or by an interposed flat piece. of metal, or otherwise. In, any case the two'plates constituting a member are riveted or bolted togetherto form'the heat-exchanger; these lamellarmembers being mounted side by side and spaced at uniform distances apart by castiron shoes or by other suitable means. This form of construction 1s always very complicated.

Heatexchangers have already been con-1 structedwith plates clamped between frames consisting partly of solid port-ionsand partly. of undulated portions, but- In all such constructions the plates and frames were specially machined andin particular bored with holes to ehgagc bolts for assembling the. whole set of plates and frames whose disassembly is then complicated. The, object of the pres-- ness.

In the accompanying drawings, which illustrate typical embodiments of the invention: j

Figure 1 represents, in perspective, two successive units of an BXChfl-DgBIQ- tht plates and frames being in position previous to locking together. 1

Figure 2 is afront elevation and Figure 3 a. plan (if-several unit's assembled to-' geth Y I are injthe-iorm ot sinecurvea end of the set.

rounding the set of plates and frames.

sp fi arneiersrat'em. Patentn Mar. 21, 1922.. Application filed October 29. 1920. Serial No. 420,460.

Figures 4 and 5 representmodifications of the frames.

Figure '6 is a sectional detail showing: a

form of joint between the frames and plates. Figure 7 is a cross section and Figure 8 a front view of anelement of .,the en-' changer comprising bracing spirals which are in form of zig-zag instead of being completely helical. and Figure 9 is a cross section or a modification in which the spirals "FigureslO and l l' are perspective views in which the smoke element and the air element respectively possess additional spi ra ls.

Figure 12 shows in cross section the inlet and outlet ends of the plates having a special configuration.

Figures 13, 14 and 15 illustrate modified formspf said ends.

in plantaken on line 17-l7 of Figure 16 SllOWlllg' the assemblage of plates and frames inside a case.

In the embodiment shown in F igures l, 2*

and 3, the first frame is composed-of bars a, a and spirals b, 7) similar to those of a spring but preferably fairly rigid, the

spirals being arranged at right angles to the bars. The next frame is made up, so far as three of its sides are concerned,(. f bars '0, c, c, the fourth side consisting of spirals r! at right angles. to the spirals b, 7) otthe first frame. Towards the middle. the spirals (l are. separated by a small bar 0 forming a baffle. Plain plates 7', f f, of sheet metal, are mounted between the frames without any preparation, and are fitted to the frames in such a way that the solid portions of these latter make contact with the plates, this contact bcing made tight enough to form a' joint by means of the pressure exerted bythe elastic spirals on the plates when the whole is clamped at the Figure 16 is a View showing the general arrangement of the exchanger inside a chim-i 1 ney fine, and Figure 17 1s a partial section ends of the assembled members at right angles to the surface of the plates. The frames 11.67) and cod are placed in succession with a plate f interposed between each of them. An angle iron 2 for instance is placed against the lastplate on either The iron2 can slide inside angle or channel irons 3 which are invariably assembled together toform a'case sur- The i 1 l i P alrengh un ainly b and issuing "an "the ,the' bailie e. The circulation spaces are 30' bounded by the barsa: and not the frames,

irons 2 can be united to the irons 3 by means gpiac'ea iertically oneig'adja 2th her fore clamping; the-set is' at firstsli glitly" 5 wider than thecase formed by the irons 3,

and the irons 2 are somewhat outside the. irons 3. By tightening the bolts 4,-"the' irons 2 are drawn close to the irons 3 and the different springs bb 'and d of the frames are slightly flattened. The resistance of said springsjs ofcourse opposed -to the drawing of the platesand frames together, but when the set is tightenedv by the bolts 4 the springs transmit tothe plates f the. pressure to which they'are subjected and thus securetightnessoif the plates on the solid parts of the'frai'nes. F

The case formedby the irons 3 containing the plates and; fra'mes'may be placed for. instance insidea chimney flue (Fi ure. 16).

I Gases, coming for instance rom a fire, circulate in ,the direction of the arrows A, o en r g; between two; adja ent Pla s:

opposite sidest roughthespirals b. vAtthe seine time, the atmospheric air to'beiheated enters and issues throughthe spirals d, in l the direction of the arrows 'B, flowing round the spirals bein' arranged so as not to appreciably-imp e thepassage of the fluids. The heated air passes mtoa conduit 5 leading said-air for instance to a blower 6 orany other apparatus wherein'itis to uti- 1 'li'zed.

Thellframe c d for the passage of the air, for example, instead of having continuous spirals along oneof the sides asvshewn in 40 Figure 1, may have one side formed of spirals g g' (Figure 4) separated by a solid bar 71-; or two of the sides of a frame-(Figure 5) maybe formed partly of spirals); k, and partly of bars m, m, according to the path which the airis desired to travel as indicated by the arrows B. The form andarrangement of .the various 1 portions of the. frames and plates,vas well as the direction of, circulation of the .fluids, may vary according to circumstances, the

solid portions, inparticular, beingof irons of anydesiredisectien,

It 't be desired to make the whole tighter filfithe joints, any suitable device ma be adopted according to the nature of the c rculating th ids; welding for apparatus re quired' tjo;;have very tight joints'or packing only ma be employed. For the-purpose contemp ated a perfect joint is not required but the. simple clamping of the plates and framestogether will be suflicient, the .principal object in view being the simplicity of the whole structure. v I

The d tail view Figurefi, tprinstance,

shews a li arrangement, comprising a chan- V of b ltset. When the platesand iraln e ie,

nel iron, in place of the bars a of Figure 1, i

need by p e e o asbes o .febi e a i. material,*raainsdfinxhehol low of the channel iron-by a friction-tight bar j. This arrangement has the advantage of preserving the simple character of the whole exchanger.

Instead of being completely helical in form, the resilient parts maybe composed of 4 strips of waved or corrugated metal, or otherwise.

In Figures 7 and 8 the bracing n arranged between the plates f of an element is constituted by a strip of steel sheet bent in a zigzag. 'Said sheet may be fastened to one of 8 the plates by a rivet 0 or any other suitable means. \Vhen the elements are clamped tospacing of the plates without preventing circulation ofthe fluid.

,guIn the case ofFigure 9,-the strip;o f metalq ;;t. 1

' is '=uiidulated with curved parts. 3

The strips according to Figures 7, 8 and 9 present the advantage of being rapidly executed by-simplymounting them' on usual -machine-tools and working them fromrolled baud-irons for instance. v v

a The plates of the heat exchanger may npt be'plane surfaces, but .curved for insta'iice, and in such case the ,braces are accordingly adapted: thereto.

g It-may occurthat'air or another fluid is sent under pressure between the plates of an element, said plates then risking to be .deformed. In order toavoid such deforma-,. tion, according to F ignites. 10 and 11, additional spirals are placed within the "element I or cell where the other fluid of the ex- 106 changer. circulates, so as to receive the load resting on the plates subjected to the pressure. I

In the example of Figure 10, combustion gases of a furnace circulate inside the frame 110 formed by the bars a and spirals 721). Additional spirals p. are located between the end spirals bb ir under pressure circulates in the ad- 1? jaceni cell bordered by the frame 015, the 11-6 plate 7 between the two cells rests on the .spirals p, the latter beirig slightly resilient .i I while being fairly rigid like the spirals b and d, and said plate will not have any a preciable deformation. Furthermore, t e multiplicity of spirals p, placed on the way of the fluid causes whirls which are favorable to the transmission of heat from one fluid to the other.

The same arrangement-may be provided 1'25 in the cell where air or any other fluid circulates, for instance-in the'case of Figure '11,

if a gasor' steam under pressure circulates in the cell bordered by the frame a. '1) i= spirals I), may be added the frame 0d. v p

Y The spirals'p or 12, instead of being complate' y hel c l,mayabiQrmsdn p t eil r; ike the 'sp'ir'als z agenda;-

' y amps-disaster When a fluid; enters one of the cells it is subjected to" a contraction which causes an appreciable loss of pressure if the contraction doesnot occur alonga suitable outline such as shown in Figure 12- In Said figure the ends of the plates f are curved at g according to a suitable angle of contraction so as to reduce to a minimum the loss of pressure; it is known that said angle approxiniates Likewise, at the outlet'of the cell, the plates j f are curved to give the best transformation of kinetic pressure into dynamic pressure, and the angle of expansion or so called diffusion approximates 7,

The ends of the curved parts q and r of the plates of two adjacent cells'may simgly ut rest on one another by their resiliency.

, in order to increase the tightness of the ele-. ments, sald ends may be formed, as in Figure to surround ;a cord i material, interposed between them.'-

Said ends instead of being formed by the plates f themselves,'may be constituted by separate V-shaped resilient members 8 (Figure 14;) resting on the portion of the plates f passing beyond the frames 0, 'or by solid members it (Cigure 15).. then be again'formed by plain sheets.

The invention is applicable to theexchange of heat l')etween'-gases, vapours or constituent members areformed by the jux v taposition of plain plates clamped between j a mi y her:,P1aStie- The plates 7 can frames formed of solid portions as joints betweenthe-plates, and oti-elastic; undulations/ I exerting pressure on th'ejpl'ates' whilst allow ing the passage of fluids.

2. A heat-exchanger for fluids comprisingplain plates clamped betweenframes, said frames being formed'partly of solid portions and partly ofj elastic undulations allowing the passage of fluids, and solid-baffles connected with the frames.

3. Aheat-exchanger for fluids comprised of plain plates, frames interposed between said plates, said frames being formed partly of solid portions and partly of elastic undulated portions allowing the passage of between said solid portions and the plates.

4. A heat-exchanger for fluids comprised of plain plates clamped between frames, said frames'being formed partly of solid portions as joints between the plates, and partly of fairly rigid elastic undulations exerting 7 pressure on thelplates whilst allowing, the

passage of fluids. '5. A heat-exchanger for fluids comprising 'fluid, and means for securing a tight joint plain plates interposed between frames r formed of solid.portions and resilient portions whose width is slightly greater than the. distance a art of the plates,said frames also. having 0t er resilient portions intermediate the edges of the plates,"and clamping means situated outside the edges of the plates and frames. i. 1 6. A heat-exchangerfor'fluids comprising plain plates, distancing frames formed ofsolid portions and undulated resilient portions, the inlet and outlet ends of theplates I being curved to give passageways for the rational circulation of the fluids;

EMILE PRAT. 

